Dielectric ceramic

Abstract

A dielectric ceramics comprises a complex oxide having a perovskite-type crystal structure, the complex oxide substantially having the composition represented by the following general formula (I) (Ba.sub.(1-x) Sr.sub.x){(Mg.sub.(1-y) Zn.sub.y).sub.1/3 ( -Ta.sub.(1-z) Nb z ) 2/3 }O 3 (I) wherein x, y and z are numbers represented respectively by the expressions 0<x<1, 0<y<1, and 0<x<1. The temperature coefficient of the resonant frequency of the ceramics can be freely changed by adjusting the x value.

What is claimed is: 
     
       1. A dielectric ceramic, consisting of a complex oxide having a perovskite-type crystal structure, said complex oxide having the composition represented by the following general formula:   (Ba.sub.(1-x) Sr.sub.x) (Mg.sub.(1-y) Zn.sub.y).sub.1/3 (Ta.sub.(1-z) Nb.sub.z).sub.2/3 O.sub.3     wherein x, y and z are numbers represented respectively by the expressions 0<x<1, 0<y<1 and 0<z<1, and (Ba, Sr): (Mg, Zn): (Ta, [<], Nb) have an atomic ratio of substantially 3:1:2.